An electronic system may be formed by a plurality of electronic circuits, each one being capable of performing a specific function of the system. Among the design issues that are encountered in the development of an electronic system, one of particular relevance is given by the coupling among the electronic circuits thereof.
In a solution being known in the state of the art and commonly used for a large number of electronic systems available in the market, the coupling among the electronic circuits is performed through electrical connections. For example, such electrical connections may be implemented by interconnection metal tracks being arranged on an insulating support that is shared among the electronic circuits.
However, such interconnection tracks are subject to parasitic effects (for example, resistive, inductive and capacitive ones) that limit the maximum frequency of the signals (thereby affecting the speed of communication and execution of the operations) and that may imply unwanted power dissipation.
A known solution of the above-mentioned drawbacks provides for the coupling among the electronic circuits through electromagnetic waves. In order to transmit and/or receive the desired signals, the electronic circuits are provided with antennas. There exist solutions in which the antennas are of capacitive type; such capacitive antennas are devices that mainly use the electric field and, by means of electric induction, translate a voltage variation into an electromagnetic disturbance, and vice-versa, depending on whether they are used for transmission or reception. However, the capacitive antennas may be capable of only transmitting and receiving signals, but not a power supply. There also exist opposite solutions in which the antennas are of inductive type and they are included, for example, in parallel resonant LC circuits (that is, formed by an inductor and a capacitor being connected in parallel). Such inductive antennas mainly use the magnetic field and they are devices that, by means of magnetic induction, translate a current variation into an electromagnetic disturbance, and vice-versa, depending on whether they are used for transmission or reception.
However, such solutions may have some drawbacks that make them not always conveniently applicable in any electronic system. Particularly, the use of resonant LC circuits (for example, of parallel type) being embedded in the electronic circuits may occupy an excessive area, and this is often incompatible with the needs of reduced size.
Such drawback may be solved by implementing each inductive antenna in an upper area of the electronic circuit (without any increase in the area occupation of the electronic circuit). However, both in the case that the antenna is formed within the electronic circuit and in the case that the antenna is formed above it, the implementation of the coupling being based on inductive antennas substantially requires that each electronic circuit being part of the electronic system should be provided with at least one resonant LC circuit. This implies an increase in the number of required components and in the production costs.